Tennis-Players will be allowed up to four Hawkeye challenges

LONDON, March 19 (Reuters) - Players will be allowed up to four unsuccessful challenges per set at any tournament that uses electronic line calling systems, tennis officials said on Wednesday.

The four tennis governing bodies -- ITF, ATP, WTA Tour and Grand Slams -- said in a statement they had agreed to adopt a unified challenge system in all professional tennis tournaments and team competitions.

Since the arrival of electronic line-calling review systems -- using Hawkeye technology -- tournaments have been allowed to set their own rules for using the system.

While some allowed players to have an unlimited number of challenges in every match, other tournaments limited them to two or three unsuccessful challenges per set.

The governing bodies said players and teams would now be allowed a maximum of three unsuccessful challenges per set plus one more if the set reached a tiebreak.

Next week's Sony Ericsson Open in Miami will be the first tournament to use the unified challenge system.

Three of the four grand slams use the technology. The French Open is the only major not to use the system as the ball leaves a mark on the clay surface.

(Reporting by Pritha Sarkar, Editing by Clare Fallon)