* BSE halts trading for about 3 hours due to network outage
* BSE CEO says looking at cause, will report to regulators
* Outage comes as BSE steps up competition against NSE (Adds quote, background)
By Abhishek Vishnoi and Rafael Nam
MUMBAI, July 3 India's second-biggest exchange operator BSE Ltd halted trading across all its markets for about three hours on Thursday due to a network outage, marking the fourth time this year the bourse has suffered from technical problems.
The latest trading disruption at BSE Ltd raised concerns about the sturdiness of the systems at a bourse that runs the BSE index, or the Sensex, considered the benchmark share index in India.
The BSE has been stepping up its competition against India's biggest bourse operator National Stock Exchange Ltd (NSE), including by adopting the Eurex trading platform owned by Deutsche Boerse AG.
The competition from the two exchanges has run from the NSE's Nifty share index to currency derivatives, and increasingly electronic and algorithmic trading.
The BSE CEO said the exchange operator was looking into the root causes of the outage and would send reports to the government and regulators.
"We need to evaluate the root cause of the network outage," said Ashishkumar Chauhan, chief executive, told reporters at a news conference.
"We will set up a panel to probe the issue and will also send preliminary reports to SEBI, and finance ministry."
The BSE had earlier suspended trading across all of its markets, and said network service vendor HCL Technologies Ltd was working to resolve the issue.
An HCL Technologies spokesman had no immediate comment.
"Due to a network outage being currently faced, BSE has decided to close all markets," the exchange said in a statement sent via text message on Thursday morning.
The BSE said it would cancel all orders placed before the network outage.
The trading disruption was the longest suffered by the BSE since at least 2010, according to a spokesman, and comes after a slew of issues this year, although a couple of those cases in April were tied to the introduction of the trading system owned by Deutsche Boerse.
"This is not desirable when we have the best of the IT players and global standards in India," said Nilesh Dedhia, founder of NTD Trading, which specialises in providing algo-based trading platforms.
"It gives a bad signal to global investors as people around the globe watch Sensex more than Nifty."
The BSE has long sought to narrow the lead by NSE, which currently dominates trading across most segments. According to data from the World Federation of Exchanges, shares worth $85 trillion were traded in the BSE in 2013 compared with $479 trillion for the NSE. (Additional reporting by Indulal PM; Editing by Eric Meijer and Jacqueline Wong)