UPDATE 2-Goldman Sachs' Schwartz retires, paves way for Solomon as next CEO

(Updates with background on departure)

March 12 (Reuters) - Goldman Sachs Group Inc said on Monday that Harvey Schwartz will retire from the bank, leaving David Solomon as sole president and chief operating officer and the most obvious successor to Chief Executive Lloyd Blankfein.

The bank did not say why Schwartz was retiring. He was seen as one of two contenders along with Co-Chief Operating Officer Solomon to take over the top spot at what is viewed as the most powerful U.S. investment bank.

Schwartz, 53, has served in his current role since January 2017. He will retire on April 20.

Goldman shares were up nearly 1.4 percent to hit a lifetime high in morning trade.

The Wall Street Journal reported on Friday that Blankfein was expected to retire as soon as this year and the bank was not looking beyond Schwartz and Solomon to replace him. Goldman did not comment on the report.

At the start of 2017, Schwartz became co-chief operating officer alongside Solomon, 56, after Gary Cohn left Goldman to become U.S. President Donald Trump's chief economic adviser.

He was a co-head of trading for years before named chief financial officer in 2012. He moved up the ranks at Goldman after starting in the trading division like Blankfein.

The unexpected announcement comes as Goldman Sachs has been trying to reinvent itself after market trends and regulations implemented since 2010 sapped profits from its once lucrative trading business.

Schwartz outlined a target to grow revenue by $5 billion a year in September, after investors pressured the bank to be more transparent about its strategy outlook. (Reporting by Parikshit Mishra in Bengaluru and Catherine Ngai in New York; Editing by Bernard Orr and Meredith Mazzilli)