Other possible winners from the Halliburton deal

A worker on a oil and gas drilling rig.
Eddie Seal | Bloomberg | Getty Images
A worker on a oil and gas drilling rig.

Halliburton's planned deal for Baker Hughes is seen as changing the competitive landscape in the oilfield services industry. But it may also present game-changing opportunities for small and mid-cap services firms, said analysts.

To push the deal past antitrust regulators, Halliburton will likely sell off some of its own business lines, including entities that are successful on their own. And that may give smaller firms the chance to grow by acquiring the divested interests. It's also likely to attract the interest of private equity firms.

"There's a lot of good businesses in there, and should some of those shake lose, that's an opportunity for the mid-caps and small caps," said Jeff Tillery, head of research at Tudor Pickering Holt.

Halliburton's CEO on antitrust opposition
Halliburton's CEO on antitrust opposition   

In a press release, Halliburton said it is prepared to part with business lines that generate $7.5 billion in revenue in order to win approval of the $34.6 billion deal from regulators, though it believes the threshold will be lower.

Read MoreHalliburton strikes deal to buy Baker Hughes

Halliburton CEO Dave Lesar told CNBC's "Squawk on the Street" that he expects many willing buyers based on early response to the announcement.

"My email box filled up with people — private equity, public companies, private companies — wanting to look at basically anything we might have to dispose of," he said.

RBC Capital Markets on Monday identified four businesses in which Halliburton is most likely to divest some of its interest: well cementing, drill bits, drilling fluids, and a data-collection technique called "logging while drilling."

There are few companies with enough cash on hand to buy a significant chunk of the divestments without diluting their stock or damaging their credit rating, said Kurt Hallead, an equity researcher at RBC Capital Markets.

Read MorePrivate equity bets on energy 'revolution' — in oil and gas

Dublin, Ireland-based international services firm Weatherford, for example, would be a logical buyer of the assets and could make it happen with a mix of cash and stock, Hallead said. The firm has a market capitalization of $12.8 billion and focuses on evaluating formations, constructing wells, and well completion and production.

But under that scenario, Weatherford would essentially become what Baker Hughes was, an outcome that might be unattractive to Halliburton.

"Does Halliburton really want to package that and recreate the competitor they just bought? Probably not," Hallead said.

"Private equity will be standing in line...to participate." -Jeff Tillery, head of research, Tudor Pickering Holt

In a piecemeal sale, oilfield services firms would likely buy complementary business lines.

Tillery speculated that Forum Energy Technologies, National Oilwell Varco and GE Energy would all be interested in the manufacturing businesses that come up. Superior Energy Services and Frank's International might be interested in the services-oriented businesses, he said.

Those companies could also face another set of rival bidders, analysts said: private equity firms.

Read MoreUS shale and OPEC oil: Game of chicken?

"Private equity will be standing in line, as well, to participate," said Tillery, adding that there's a relatively long list of firms with an interest in Halliburton's business interests.

A private equity firm could potentially buy and integrate individual interests into another asset under its management. It is also possible that a single firm or consortium would purchase a portfolio of Halliburton's businesses, package it as a new company and take it public, Hallead said.

But that, again, could create a fairly large competitor, and it remains to be seen if such a result would be acceptable to Halliburton.

More M&A? Not necessarily

The Halliburton and Baker Hughes deal is unlikely to spur further mergers and acquisitions, because in that sector, there's no disadvantage to being a small, niche player, Tillery said.

"I don't think [the deal] forces a reaction by other folks," said Tillery. "This is more about Halliburton trying to close the gap globally relative to (its rival) Schlumburger. So many of the other companies either just sell products into the global services business or are primarily North America focused, so it doesn't impact them in any great way."