UPDATE 1-French growth hits six-year high as investment, exports spurt

* Q4 growth clocks in at 0.6 pct Q/Q after 0.5 pct in Q3

* Full-year GDP growth strongest since 2011 at 1.9 pct

* Capacity constraints building as momentum picks up (Adds details, quotes)

PARIS, Jan 30 (Reuters) - The French economy rounded off its strongest year since 2011 with quarterly growth boosted by a spurt in business investment and exports in the final three months, official data showed on Tuesday.

The euro zone's second-biggest economy grew 0.6 percent in the October through December period from the previous quarter when it grew 0.5 percent, the INSEE official statistics institute said.

The reading, which was in line with economists' average expectations, meant that for 2017 as a whole, the economy grew 1.9 percent, which means France had its best year in terms of growth last year since 2011.

Finance Minister Bruno Le Maire gave credit for the strong showing to surging consumer and business confidence since President Emmanuel Macron's election in May, and reforms undertaken since then.

"According to the latest indicators, this trend should keep up in 2018," Le Maire said in a statement.

The full-year growth rate exceeded the 1.7 percent on which France's budget was based, which increases the chances that France achieved its pledge of cutting the public sector deficit to less than three percent of gross domestic product last year for the first time in a decade.

After years of mediocre growth, businesses are increasingly struggling to take on workers and expand factories fast enough to keep up with demand.

"There's not much spare capacity for the economy to absorb now that growth has strengthened. With the outlook remaining positive over the next two years, capacity constraints and domestic inflationary pressures may well rise," Morgan Stanley economists wrote in a research note.

In the fourth quarter, growth in consumer spending - traditionally the motor of the French economy - slowed to 0.3 percent from the previous three months.

But business investment helped offset slower consumer spending, growing 1.5 percent, as corporate confidence soared and industrial companies faced growing production bottlenecks in the face of strong demand.

Overall, domestic demand contributed 0.5 percentage points to growth in the quarter while companies drawing down inventories subtracted 0.5 percentage points.

Foreign trade contributed 0.6 percentage points to overall growth thanks to the strongest increase in exports since the second quarter of 2010.

(Reporting by Leigh Thomas; Editing by Sudip Kar-Gupta)