Greek losses curb gains on European stock markets
* FTSEurofirst 300 index up 0.6 pct
* Athens bourse falls, hit by ongoing political uncertainty
* Upbeat economic news lifts Madrid and Lisbon markets
* FTSE up but pares gains as UK external deficit rises
By Sudip Kar-Gupta
LONDON, Dec 23 (Reuters) - A fall in Greek stocks kept a lid on gains in European equities on Tuesday, as the Athens bourse was hit by the prospect of early elections that could put Greece's rescue package at risk.
The pan-European FTSEurofirst 300 index was up by 0.6 percent at 1,374.59 points going into the close of the trading session, with the index up 4.4 percent since the start of 2014.
European stocks were helped by positive economic news from Spain and Portugal.
The Bank of Spain raised its economic forecast while Portugal's budget deficit shrank to 4.3 percent of gross domestic product in the 12 months to the end of September from 4.8 percent a year earlier. Continuación...