(Julie Jacobson, File/AP Photo)

The Pentagon on Thursday will propose rule changes that will allow more women to formally serve in jobs closer to the front lines.

Defense officials say as many as 14,000 positions could be opened up, though the restrictions on women serving in infantry combat units will remain in place.

The rule change reflects the ongoing reality that in a decade of war in Iraq and Afghanistan, women were already dying in combat with the blurring of the traditional definition of front lines. Nearly 300,000 women have served in the wars in Iraq and Afghanistan and 144 of them have died in those conflicts.

The rule change is included in a report required by Congress as part of last year's Defense Authorization Bill that has been overdue for months. The new rules likely will not go into effect until the summer if Congress raises no objections to the change.

Women will still be barred from serving in infantry combat units, defense officials say, but the changes will formally open up new positions at the combat battalion level that, until now, have been off limits.

The new jobs opening up for female service members will be combat support positions, including communications, intelligence and logistical positions, defense officials add. Typically, these jobs have been made available at the combat brigade level, but not at the lower battalion level, which was deemed too close to combat situation.

However, the insurgent nature of the wars in Iraq and Afghanistan has blurred the line for combat situations. That often meant that all units likely could be exposed to some combat, including units where women were allowed to serve.

For example, in Iraq it was a regular occurrence that units that were technically not combat units were seeing combat. For example, women have been allowed to serve in military police units for years, but when those units were dispatched to Iraq to provide security and training, they were often under risk of attack.

In 2005, Sgt. Leigh Ann Hester, serving with a military police unit in Iraq, became the first woman to receive the Silver Star since World War II. Hester received the medal for valor for her role in fighting off a large insurgent attack on her convoy.

The rules to be announced Thursday will apply to all of the military services, but will have the greatest impact on the Army, given the large number of ground combat units it has.

A year ago, the Military Leadership Diversity Commission recommended that the military lift the ban on women serving in combat units.

The advisory panel of current and retired military officers said that keeping women from serving in combat units was an obstacle to promotions and career advancement.