UPDATE 2-Ryanair upbeat on profit; keeps door ajar for Boeing

* Could slightly raise FY earnings guidance

* Dec passengers 4.9 mln, up 12 pct y/y

* To scale back capex after pulling out of Boeing talks

* Fresh bid for Aer Lingus "highly unlikely"

(Adds market reaction)

DUBLIN, Jan 7 (Reuters) - Irish airline Ryanair (RYA.I) said it could slightly raise its full-year earnings forecast after a strong third quarter, and left the door ajar for a possible resumption of talks with Boeing Co (BA.N) over aircraft orders.

Ryanair said it planned to return at least 1 billion euros in cash to shareholders through some combination of share buybacks and distributions from 2013 as it cuts capital expenditure by more than 90 percent after ending talks to buy 200 aircraft from the U.S. planemaker.

Ryanair, Europe's biggest low-cost airline and close to being the biggest carrier overall, denied reports it was preparing a third bid for Irish rival Aer Lingus (AERL.I).

"In the absence of any decision by the Irish government to sell its 25 percent stake, a third bid by Ryanair remains highly unlikely," Ryanair said in a statement on Thursday ahead of an investor briefing.

"We expect our current cash reserves of 2.5 billion euros to grow substantially by March 2013 and we plan to distribute surplus cash to shareholders from that date."

Ryanair already said last month it would reduce capacity growth from 2011 and return surplus cash to shareholders from 2012-2015, and Chief Executive Michael O'Leary told analysts he was not ruling out a fresh order if Boeing improved its terms.

A Dublin-based equities trader said that O'Leary, known for driving hard bargains, could still be trying to exert pressure on Boeing and he could also reevaluate his position on Aer Lingus.

"It's really hard to judge the guy or to work him out, he's a good card player," the trader said.

Ryanair's passenger traffic in December grew 12 percent to 4.9 million, bringing the number for the calendar year to 65.3 million, which it plans to raise to more than 66 million in the business year to the end of March.

At 1130 GMT, Ryanair shares were down 2.3 percent at 3.45 euros.

(Reporting by Andras Gergely; Editing by Hans Peters)